The present invention relates to a process for the preparation of 2-chlorobuta-1,3-diene (chloroprene) by dehydrochlorination of 3,4-dichlorobut-1-ene. It is known from DAS (German Published Specification) 2,310,744 to dehydrate aqueous sodium hydroxide solution azeotropically using n-butanol and to react the solution of sodium butylate in n-butanol, obtained in this way, with 3,4-dichlorobut-1-ene in the liquid phase to give a reaction mixture which essentially consists of chloroprene, n-butanol and suspended sodium chloride. It is further known, from DAS (German Published Specification) 2,310,744, to separate off the solid sodium chloride, formed during the reaction, by mechanical means, for example by centrifuging, and subsequently to remove the chloroprene by distillation from the product which is free from sodium chloride.